Conor McGregor attended UFC 223 despite his media day shenanigans earlier in the week. The UFC's most entertaining fighter wasn't going to miss warching the fights in person no matter what.
As upset as Dana White appeared to be, it's hard to believe that McGregor would be permitted to attend. He either snuck in or this is a very good lookalike.
If it is really McGregor, he's got the biggest balls on the planet. That's why we love watching him.